<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>伪元素</title>
  <style>
    *{
      margin: 0;
      padding: 0;
    }
    .container{
      max-width: 600px; /*  适配 移动端就用自己的宽度 PC端mw  */
      margin: 0,auto; /*左右水平居中*/
      padding: 20px;
      font-family: Arial,sans-serif;
    }
    h1{
      text-align: center;
    }
    p{
      line-height: 1.6;
    }
    .more{
      /* display css格式化上下文 定义元素的布局规则  */
      display: inline-block;
      padding: 10px 20px;
      background-color: #007bf0;
      color: white;
      text-decoration: none;
      position: relative;
      /* 过渡动画 */
      transition: all .3s ease;
    }
    .more::before{
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background-color: yellow;
      transform: scaleX(0);
      transform-origin: bottom left ;
      transition: transform .3s ease;
    }
    .more:hover::before{
      transform: scaleX(1)
    }
    .more::after{
      display: inline-block; /*！*/
      content:'\2192';
      margin-left: 5px;
      transform: transform .3s ease;

    }
     .more:hover:after{
      transform: translateX(5px);
    }
  </style>
</head>
<body>
  <div class="container">
    <h1>示例标题</h1>
    <p>这是一个段落，</p>
    <a href="#" class="more">查看更多</a>
  </div>
</body>
</html>